FENOLOGÍA DEL COSCOROBA (COSCOROBA COSCOROBA) EN EL SUR DE BRASIL Y SUS MOVIMIENTOS HACIA ARGENTINA

Phenology of Coscoroba Swan (Coscoroba coscoroba) in southern Brazil and their movements to Argentina. - The Coscoroba Swan (Coscoroba coscoroba) is an unusual member of the Anatidae. It has a patchy distribution and is a partial migrant found from the Falkland Islands and Tierra del Fuego through Chile and Argentina, Uruguay, and Paraguay as far north as Mato Grosso do Sul in Brazil. This study describes the movements of Coscoroba swans banded outside the boundary of and in side the "Estacao Ecologica do Taim" Reserve (c. 32°33'S, 52°32'W) in the southern coastal plain of the State of Rio Grande do Sul, Brazil and the phenology in this area. The analysis of banding and recapture or recovery data was conducted between 2005 and 2008, and data from birds marked between 1979 and 2006 were also obtained from "Centro Nacional de Pesquisas e Conservacao de Aves Silvestres" (CEMAVE). Distance between sites, the location of marking and recapture or recovery sites, and sex and age were analyzed. A total of 1070 birds were banded and ringed during the flightless wing moult and 32 recaptures or recoveries were registered during the study period (27 inside the banding area and five outside), the resighting of a Coscoroba in Chubut, Argentina (43°21'S, 65°03'W) being most noteworthy. A route between Argentina and Brazil to the central depression of Rio Grande do Sul state (to and from the Taim area) was confirmed as well as fidelity to Taim as a molting site and important breeding area. Recaptures at Taim showed a prevalence of male adults that may indicate a greater male fidelity to the natal area and juvenile dispersal to other areas until sexual maturity is reached.